Every API is a thin adapter over an offline, fail-closed fact engine. No accounts, no API keys. Soon, agents pay per request via x402 (USDC, settled at the edge).
| API | What it answers | For agents | For humans | Status |
|---|---|---|---|---|
| iban | SEPA-wide IBAN validation (bank, BIC, LEI, reachability) and fail-closed German BLZ/Konto → IBAN calculation against the complete Bundesbank rulebook — the correct IBAN or a refusal, never a guess. | iban.api · openapi | iban.chrisked.de | live — free MVP |
| lei | LEI lookup, search, entity matching, and corporate trees (GLEIF). | lei.api · openapi | lei.chrisked.de | live — free MVP |
| vat | EU VAT number validation with consultation numbers, live against VIES — a real verdict or a machine-readable refusal, never a guess. | vat.api · openapi | vat.chrisked.de | live — free MVP |
| esim | eSIM data plans: catalog, checkout, issuance and activation materials. | esim.api | esim.chrisked.de | proof of concept |
| letter | DIN 5008 government letters as archival PDF/A-2b, rendered from structured input. | — | — | scaffolded |
Family layout: <product>.api.chrisked.de
is the agent/developer surface — the interactive API reference at
/, the machine-readable contract at /openapi.json.
<product>.chrisked.de is the human product site with a
live demo.